Support for pluggable apps. e.g. we do have a "users" app which provides user registration, authentication and social integration. Is this something like Rack

Support for pluggable apps. e.g. we do have a "users" app which provides user registration, authentication and social integration. Is this something like Rack (in Ruby on Rails)? Also your templating system looks very similar to Handlebar/Mustache - is that what the general principles are going to be ?